bake

= Bake

Go Build + Something like Make = Bake ¯\_(ツ)_/¯ 🤷

Bake is a Make like tool that allows you to define and run tasks defined in Go code under a `bakefiles/` dir.

* Tasks have a fully featured argument parser.
* It allows you to see the description of the tasks and subtasks and autocomplete them and their options.
* It also bundles a DAG runner that allows you to make tasks depend on other tasks.
* Built-in cancellation context for tasks.

== Getting Started

In any directory, run: `bake _bake init` to create a `bakefiles/` directory with an empty project.

Then run: `bake` to see the available tasks.

== Install

* Install using homebrew:
+
----
brew tap DavidGamba/dgtools https://github.com/DavidGamba/dgtools
brew install DavidGamba/dgtools/bake
----
+
[NOTE]
====
Completion is auto setup for bash.

For `zsh` completions, an additional step is required, add the following to your `.zshrc`:

[source, zsh]
----
export ZSHELL="true"
source "$(brew --prefix)/share/zsh/site-functions/dgtools.bake.zsh"
----
====
+
Upgrade with:
+
----
brew update
brew upgrade bake
----

* Install using go:
+
Install the binary into your `~/go/bin`:
+
----
go install github.com/DavidGamba/dgtools/bake@latest
----
+
Then setup the completion.
+
For bash:
+
----
complete -o default -C bake bake
----
+
For zsh:
+
[source, zsh]
----
export ZSHELL="true"
autoload -U +X compinit && compinit
autoload -U +X bashcompinit && bashcompinit
complete -o default -C bake bake
----

=== Gitignore

Add the following to your global gitignore file:

.~/.gitignore
----
**/bakefiles/bake
**/bakefiles/generated_bake.go
----

== Example Task

NOTE: A more in depth example can be found link:./examples/website/README.adoc[here].

Copy the following into a new `bakefiles/main.go` file after running `bake _bake init`:

[source, go]
----
package main

import (
	"context"
	"fmt"

	"github.com/DavidGamba/go-getoptions"
)

// say:hello - This is a greeting
func Hello(opt *getoptions.GetOpt) getoptions.CommandFn {
	var lang string
	opt.StringVar(&lang, "lang", "en", opt.ValidValues("en", "es"))
	return func(ctx context.Context, opt *getoptions.GetOpt, args []string) error {
		Logger.Printf("Running say:hello\n")

		switch lang {
		case "en":
			fmt.Println("Hello")
		case "es":
			fmt.Println("Hola")
		}

		return nil
	}
}
----

Run it:

----
$ bake say hello
2023/04/10 14:58:34 Running Hello
Hello

$ bake say hello --lang=es
2023/04/10 14:58:38 Running Hello
Hola
----

== How does it work?

Bake is a Make like tool that allows you to define and run tasks defined in Go code under a `bakefiles/` dir.

First it searches for `bakefiles/` inside the current directory,
next it searches to see if the current directory is named `bakefiles/`,
finally it searches for a `bakefiles/` directory in the parent directories.
This allows to run bake from anywhere in the repo.

Once a `bakefiles/` dir is found, it will parse the AST of the Go files in that directory to find functions that match the proper signature.
It will then generate an entry point file (`generated_bake.go`) that uses those functions, this file is auto-generated any time your source code changes.
Finally it will compile the Go binary and run it.

Having a go binary that bake runs allows you to debug your code directly without having to worry about bake's internals.
The binary is only recompiled if the source code is changed (using https://github.com/DavidGamba/dgtools/tree/master/fsmodtime[fsmodtime]).

The bake binary loads your functions as tasks and subtasks and makes them and their options available for completion.

The bake Task signature  is `func(opt *getoptions.GetOpt) getoptions.CommandFn`.
The functions are loaded as https://github.com/DavidGamba/go-getoptions/tree/master[go-getoptions] commands and subcommands, by parsing the comment description.

For example:

[source,go]
----
// say:hello - This is a greeting
func Hello(opt *getoptions.GetOpt) getoptions.CommandFn {
	return func(ctx context.Context, opt *getoptions.GetOpt, args []string) error {
		return nil
	}
}
----

If there is no comment found for the function, the function name will be automatically converted to kebab case.

The above function will generate two commands, one for `say` and one for `hello`.
The description for the `hello` command will be `This is a greeting`.

Since the tasks are added to the bake command's `go-getoptions` instance, completions are automatically generated.

It also adds the task to the global task map, the task will automatically be added as `say:hello`.
This allows to generate custom task graphs using https://github.com/DavidGamba/go-getoptions/blob/master/dag/README.adoc[go-getoptions DAG].

== Debugging

To debug your program go to the `bakefiles/` directory and run `bake` and you should see the `bake` binary.

Set your IDE Debugger to run `./bake` with the proper arguments for your task.

To print `bake` traces, set the env var `BAKE_TRACE=true`.

== ROADMAP

* Currently not all `go-getoptions` types are supported.

* Helper for automated cancellation on timeout when passing -t flag.

* Ensure exit codes get passed through.